A priori, there are \(3vw\)  torus invariant irreducible curves in \({F_{\textnormal {\textsc {mb}}}}\) , but these satisfy standard hexagon relations (Eq. REF ), so it is possible to choose a basis of \(vw + 2\)  curves, consisting of \(v \times A\)  curves, \(w\times B\)  curves, and \((v-1)(w-1)+1 \times C\)  curves. For the small examples we consider, we will index the curves in each family in a simple way. It is possible to use a systematic choice of generators and labels for the general case [1]}, but it would be notationally cumbersome for these examples, so we do not present that here.
